RAD SPD-E1 E1 to T1 Rate and Interface Converter

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RAD SPD-E1 E1 to T1 Rate and Interface Converter


  • The SPD-E1 Rate and Interface Converter enables E1 equipment to utilize two T1 transmission links, by converting any E1 frame (2.048 Mbps) into two T1 frames(1.544 Mbps). SPD-E1 is transparent to the E1 framing pattern.
  • Jitter attenuation on each side guarantees smooth, jitter-free operation.
  • T1 parameters include D4 or ESF framing and AMI or B8ZS codes. In the ESF format, T1 main link statistics are stored in memory, in compliance with both ANSI and AT&T standards, and may be retrieved by the service supplier, or by the user via the supervisory port.
  • Timing options cover all timing situations. These include:
    • Transparent timing: T1 transmit clock of both links is locked to E1 receive clock, and E1 transmit clock is locked to T1-A receive clock.
    • Loopback timing: T1 transmit clock for both links is derived from T1-A receive clock. E1 transmit clock is derived from E1 receive clock.
    • Internal clock: Internal oscillator is the source for both E1 and T1 transmit clocks.
    • Station clock: The source for both the E1 and T1 transmit clocks is the framed/unframed all "1"s T1 (AMI).
  • Independent elastic buffering in each direction compensates for short term deviations in timing sources. Buffer size is 16 E1 frames (4096 bits).
  • The E1 frame (256 bits) is equally divided between both T1 frames, utilizing timeslots 1 to 16 of each T1 link. Spare bandwidth may accommodate an additional DTE data channel.
  • Data rates for the data channel are selectable for any multiple of 56 or 64 kbps, up to 1024 kbps. The DTE channel interface is available as V.35 or RS-530/RS-422.
  • Setup, control and monitoring of status and diagnostic information can be performed via an ASCII terminal. Setup of the basic unit can also be performed via internal jumpers. Automatic dial-up is also supported whenever an alarm event occurs.
  • Diagnostic loopbacks, activated either from the front panel or from the ASCII terminal, include:
    • E1 loopback towards the local DTE;
    • T1 loopback on both links, towards the remote DTE;
    • T1 network line loopback with carrier code activated on each T1 link.
  • SPD-E1 is available as a desktop unit, with rack mount hardware for mounting in a 19'' rack.


  • Converts an E1 frame into two T1 frames
  • Enables E1 equipment to operate over T1 facilities
  • Additional data channel: n x 56 or n x 64 kbps
  • Transparent to E1 framing
  • Controlled slip for buffer overflow/underflow
  • Loopback capabilities
  • Built-in CSUs on the T1 links
  • T1 interface complies with AT&T TR-62411, PUB 54016
  • E1 interface complies with ITU Rec. G.703, G.823
  • 24 hour storage of T1 line diagnostics
  • Automatic dial-up upon alarm event

E1/T1 Rate and Interface Converte

* Specify:
115 for 115 VAC supply
48 for -48 VDC power supply
# Specify data channel interface:
V35 for V.35 interface
530 for RS-530/422 interface
(Default is V.35)





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email us at sales@data-connect.com
or call 301-924-7400